Reflection of Point onto Plane

If P(1,-2,4) is reflected in the plane with equation 2x-3y-4z+66=0, determine the coordinates of its image point, P'. (Note that the plane 2x-3y-4z+66=0 is the right bisector of the line joining P(1,-2,4) with its image).

so when i made them equal to each other with their parametric equations, i got A(1,-2,4).
This is the same as l1.. this doesn't make sense. What did I do wrong? can you show me how you get the correct answer?